"The big question now, of course, is whether the thinning will continue at this rate or slow down. Hopefully this will become clear in years to come."
Yep. For example the paper is about thinning ice doesn't say whether its melting or floating away. There is also no timeline so while we have the average rate of change there is no sense of variability over time. I'm doing something I generally really hate, which is to criticize a piece of science for what it doesnt contain rather than look at what it does. I guess Im greedy for the bigger picture answers.

I remembered a paper published a while back that gave some insights into variability in ice arch formation in the Nares Strait.
http://onlinelibrary.wiley.com/store/10.1029/2009GL041872/asset/grl26771.pdf?v=1&t=i689jmtb&s=9a9df9ba3b64a44dd8a201571681e0d3b3b209b3
Even in the short length of years covered by this paper you can see in table 1 that arch formation can be very variable from as early as early December thru to April. Given that conditions can be such that arches fail to form thru most of the winter it doesn't seem that much of a stretch to think arches could form and break up within the winter season.
Actually reading more carefully in section 4 they talk about the formation of short lived arches in unusual parts of strait.
Still this years observation is interesting.

I don't know what the most interesting forum thread on the planet was last week, but this week it's definitely the Nares Strait thread, over on the Arctic Sea Ice Forum. All who regularly follow Arctic events, know that one of the coolest places in it is Nares Strait, the waterway between Elles...

Neven to stretch your basketball analogy a bit further, any team that ignores rebounds is going to lose the game! ( caveat I know as little about basketball as I do about climate science)
I would have thought the past two years would have taught us a little more about the role of internal variability/dynamics on arctic ice.It seems particularly interesting because its moving in the opposite direction to the way we might expect radiative forcing to affect the ice.

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: The 2014 trend line is showing the same curve as previous years, which means it stays well above the ...

Given that some of the discussion here is about atmospheric circulation/dynamics I thought I'd draw peoples attention to this new paper in discussion
Recent summer Arctic atmospheric circulation anomalies in a historical perspective
A. Belleflamme, X. Fettweis, and M. Erpicum
The Cryosphere Discuss., 8, 4823-4847, 2014
www.the-cryosphere-discuss.net/8/4823/2014/tcd-8-4823-2014.pdf
it looks at recent changes in circulation over the arctic, how it may affect ice melt and compares it to the past >100years.
heres my summary of it, people can disagree with what I've highlighted as important.
The paper is looking at the frequency of daily high pressures over different parts of the arctic. It identifies two patterns (type2 and type4) that it shows have doubled in the 2007-2012 period compared to the long term average. these type are highs over Beaufort and highs over Greenland, these are both good for increases in melting sea ice and GIC. They construct an historical record of these circulation patterns and compare this recent event to past events. They find similar departures for these two patterns in the past although given we are still going through the present anomaly its not possible to say whether the present is outside 'natural variability'. They do mention though that these departures are seen ~100 years ago when presumably both the global and arctic temperatures were cooler.
What does this study prove? I like to think whats plausible as there seems to be enough uncertainty and insufficient data to make firm conclusions (as is often the way).
It seems plausible (maybe even likely) that multi-annual to decade changes in atmospheric circulation have contributed to the post-2007 melt. I think if you look at their graphs you could say that the type2 circulation has been high since 1980s with the present departure coming on the back of that and the type4 has been increasing since the late 1990's
Attribution of what cause these changes (crudely is it natural or anthro or a bit of both) is impossible from this paper but to me it seems evidence points to it (at least) in part being natural. For example similar events occurred at the end of the 19th century when presumably global and arctic temps were lower and sea ice was higher.
How the future develops might help to understand this. they note just what a huge reversal 2013 was. The daily occurance of these two circulation patterns went from way above the historical average to way below. I;m guessing 2014 is similar. presumably if this continues forward in the future then we may get a better idea how the present circulation anomalies compare to historical events and also to what extent its natural and to what extent its had an impact on declining ice.

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: Last month I wrote: If this keeps up until the minimum, the 2014 melting season will have been excel...

Correction: the metric i looked at in the past was ice gain ( increase from minimum to maximum). I don't know what the seasonal losses look like for each year making me even more curious to see how this year stacks up

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: After a month of weather that was mostly good for ice retention (see last ASI update), volume decreas...

One interesting metric might be the total volume of ice to melt ( or be exported) this season compared with previous years. With the maximum volume in March being one of the lowest and the minimum volume (september) looking like it will be at the higher end of the post-2007 years then it could be that volume loss might be at the lower end of the whole. I looked at this number in the past and found that the pre-2007 years all generally had quite similar seasonal volume losses while post-2007 the numbers became more variable. It would be interesting to see whether this year has returned to the pre2007 volume losses or possibly is even lower.
Somebody who has the piomas data could do this calculation upto the present date or maybe its one to save foor the end of the season

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: After a month of weather that was mostly good for ice retention (see last ASI update), volume decreas...

I thought my original position was consistent with AGW theory. without extra heat in an accessible place in the NH then there is no reason for the Arctic to keep warming. Of course internal feedbacks may still be in play but at some point a new equilibrium is going to be reached until warming recommences.I dont have any firm idea how long (or how much) feedbacks continue to amplify warming beyond the initial external forcing but I do think nobody is suggesting its a runaway process.

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2013 period (NSIDC has...

One of the reasons for setting up the Arctic Sea Ice Forum, was to increase interaction and make more space for visual gems that do not fit the narrow comment section of this blog (check out for instance the Jakobshavn glacier thread). One of those gems was posted yesterday by commenter epiphyt...

jdallen_wa
I have to be brief and write in note form
i dont have citations was using KNMI climate explorer to look at data sets e.g. For the NH midlatitudes I took Hadcrut4 (20N to 60N) and get this
http://climexp.knmi.nl/data/ihadcrut4_0-360E_20-60N_n_1979:2014a.png
OHC for the Atlantic is NODC I get this
http://climexp.knmi.nl/data/inodc_heat700_-60-10E_20-60N_na.png
For AMOC, yep I like the Elliott line work, I think there is more insight to be gained from it than just the quote you highlight. But as well as that work there is also a study called US AMOC/UK RAPID which is shorter but shows a similar situation. You need to hunt for poster and publications based on that study
(Id give you a fuller answer if I was on a more user friendly device sorry)

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2013 period (NSIDC has...

It doesn't seem too implausible to think come mid-Sept that we might be in pre-2007 territory WRT CT area although lower does seem more likely.
General conditions in the NH midlatitudes more resemble the early 2000's than post-2007 conditions. Tropospheric temps are unchanged for ~15 years. Atlantic Ocean surface temperature, heat content and the heat being transported by the AMOC north all seemed to show peaks in the mid to late 2000's with present conditions a little cooler. Given these are the sources of heat for the Arctic it seems about right that arctic ice should start to return to pre-2007 condition unless things at mid-latitude change. Of course there are internal feedbacks, these may or may not have worked their way through the system for the earlier warmer period, so there may be more melting from that. All things being equal though it seems a small increase in ice, say back to 2003-2006 conditions wouldn't be outside expectations.

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2013 period (NSIDC has...

Neven you made a passing nod but I think it's worth highlighting.
The Barentz Sea has been ice-free for much of this season and had one of the lowest maximum extents. Yet as you're SST graphs show the ocean surface temps are far, far lower this year than in recent years. Given that in the past an explanation for the hot temperatures was sun beating down on ice free ocean then what would be an explanation for these lower temperatures?

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2013 period (NSIDC has...

Blaine sorry for the delay but I tried a bit of scientist bothering and emailed PolarPortal about the apparent discrepancy between the GRACE data and reported mass balance. Here is their reply, it seems like the GRACE data for the 2013 summer is unavailable (they just infilled the grapg for that period)
"Your question is really good, and the answer is actually quite simple: The GRACE mission is already way past the originally intended duration, but the satellites are still flying. But systems do fall out once in a while and, as an example, the 2013 summer data are unavailable due to power system problems. The 2013 summer data are thus missing from the Polar Portal GRACE figure. The linear interpolation across the summer negative peak suggests an extremely low (even no) loss summer and therefore is very misleading. We will work on a different way of representing this."

Here's a re-post of the NSIDC's Greenland Ice Sheet Today website, but let me also draw attention to this wonderful new resource, Polar Portal, set up by various Danish scientific research organisations. It has various maps and graphs depicting the situation on Greenland, but also the rest of th...

Blaine I'm surprised to hear God isn't involved in the calculation ;)
I hope you'll bare with me a little longer because I'm trying to get my head around all the different 'data' source.
GRACE - this is gravity measurements from satellites and gives the overall change is mass. This requires a model to convert the raw satellite data into changes in mass? We (I mean you) are happy with this data?
SMB - This is model output of snow accumulation, evaporation, melting sublimation(?) at the surface? Based on weather inputs to a model(temp, wind, snowfall etc). You are saying you think this may have gone a bit wonky for the 2013 season?
Discharge/carving/melt at glacier front. - Annual estimates are based on ....what method? Or this just derived from the difference between GRACE and SMB? Or calculated independently for each season?
There seems to be a mismatch. I'm not seeing how that is arising. Or are you saying it's not clear which bit is off?
thanks

Here's a re-post of the NSIDC's Greenland Ice Sheet Today website, but let me also draw attention to this wonderful new resource, Polar Portal, set up by various Danish scientific research organisations. It has various maps and graphs depicting the situation on Greenland, but also the rest of th...

Thanks for the explanation.
So if I understand you could describe the 2013 season as relatively quiet season for Greenland.
A typical (recent) year is that there is there is normally a rather large nett accumulation of mass at the surface. This is offset by an even larger mass carving and melting in the ocean terminating glaciers.
The 2012-2013 season there was a smaller net accumulation at the surface (but still positive). The winter looked normal but summer showed a greater nett loss than normal. But there was very little iceberg carving that year so overall the total mass of Greenland changed very little.
Although surface mass balance is obviously a big factor it looks like variability in carving events can really swing things one way or another when it comes to overall mass change of Greenland ice.

Here's a re-post of the NSIDC's Greenland Ice Sheet Today website, but let me also draw attention to this wonderful new resource, Polar Portal, set up by various Danish scientific research organisations. It has various maps and graphs depicting the situation on Greenland, but also the rest of th...

Thanks for the link, lots of pretty images.
I'm confused though. The website has this mass balance graph on it
http://polarportal.dk/fileadmin/polarportal/mass/Grace_curve_La_EN_20140100.png
I always assumed this was the total mass change of the icecap, that is how this GRACE data has been presented. It shows little mass change over the full melt/accumulation cycle for 2013. This is in contrast to the previous large 2012 season. Yet the report says there has been a lerge mass loss (equal to 1.2mm) So what am I not understanding?

Here's a re-post of the NSIDC's Greenland Ice Sheet Today website, but let me also draw attention to this wonderful new resource, Polar Portal, set up by various Danish scientific research organisations. It has various maps and graphs depicting the situation on Greenland, but also the rest of th...

Magma says "This is starting to look like yet another example of bistable behavior with tipping points"
The curious thing is why with all these tipping points it seems the earth was perched on the edge waiting for humanity to push it over. Why shouldn't the tipping point be now or in 20oC time?

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: During the month of February the gap between this year and the other years from the post-2010 period ...

Interesting the discussion drifted to PIOMASS. If ice bridges can be characterized as dynamical processes, with no clear relation to thermodynamics. And if they contribute to overall ice volume by regulating ice loss through the Nares strait, I think I've read maybe 10% of the exported ice leaves via Nares. And if there formation can be quite variable, I've read the date of their formation and collapse can vary. Then I'm wondering if anybody knows if PIOMAS can take account of these types of dynamical changes in calculating ice volume. Maybe the final impact is quite small and these sorts of variations are contained in the error bars?

This remains one of my favourite fascinating events in the Arctic. University of Delaware professor in oceanography Andreas Muenchow, the Nares Strait go-to guy, posted the following on his Icy Seas blog: Formation of Nares Strait Ice Bridges in 2014 Darkness and cold covers North Greenland, El...

Wili said
"So should we be using these CryoSat numbers or the lower PIOMAS numbers ........ (Of course, both show dramatic ice loss over the decades.)"
Sorry the pedant in me couldn't let this slide by. It's not possible for a satellite that's been generating data for 4 years to tell us anything over the decades. Just 4 years!
My wider point can be summed up by something a lecturer at university once said, from a google search it appears to originate from the geneticist William Bateson. Bateson's advice was to "treasure your exceptions". My understanding of that is to take note of observations that confound your expectations, it's data like this that has the potential to give greater insight into what is occurring more generally in the arctic. Yet most commentary seems to want to do little more than label this data point as weather and then move on.
Also I see ESA's point that the MYI has undergone a recovery but their data suggests to me that the 'recovery' is much more extensive than that (Barentz being the exception). The map for 2013 shows cyan/green extending much further into the Arctic than previous years and for that phenomenon to be homogenous over all the regions were ice is present. Shorthand, the ice is thicker everywhere (almost)!
And finally a question. Why do we have to call this weather? The great clearout of MYI in 2007 was weather. Why can't we say all the post-2007 data is weather given the large impact that year and subsequent storms etc have had. It seems rather one sided to invoke weather for the years when ice loss is less.

We have monthly PIOMAS updates, a new sea ice thickness product derived from SMOS brightness temperatures was presented earlier this month (see video), and now it's time for some more news from the third of the thickness trident: CryoSat-2. From the European Space Agency website: Arctic sea ice...

Here's a first open thread for this freezing season, which will be followed by monthly instalments. I apologize yet again for having been so inactive on the blog. I'm the kind of person who shuts off certain activities when being too busy with momentarily higher-priority stuff, but with the exte...

AFU I don't see why on this issue you should think that JC is at odds with your thinking. The mainstream seems to, at least in part, invoke 'internal variability' to explain the pause, all the Wyatt paper seems to be doing is trying to put flesh on the bones of that idea. The stadium wave may not turn out to be the explanation but something has to. The present situation where variability is seen as little more than the residual in an analysis has to be put behind us. The pause is going to be the impetous for others to get involved ( actual others are already there)

Here's a first open thread for this freezing season, which will be followed by monthly instalments. I apologize yet again for having been so inactive on the blog. I'm the kind of person who shuts off certain activities when being too busy with momentarily higher-priority stuff, but with the exte...

Except that it does appear as though the Atlantic waters moving north to the Arctic peaked in temperature around 2007.
http://prj.noc.ac.uk/ExtendedEllettLine//research-and-impact
A "recovery' in the ice extent in the Barentz/Kara would make sense, everything else being equal.

Here's a first open thread for this freezing season, which will be followed by monthly instalments. I apologize yet again for having been so inactive on the blog. I'm the kind of person who shuts off certain activities when being too busy with momentarily higher-priority stuff, but with the exte...

So the possibility of another crystal-ball gazing game in the arctic.
This graph shows that the winter maximum of the CT ice area hasn't broken 14 million for 10 seasons
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.area.arctic.png
Given the spooky melt season this year what are the chances that that particular upper limit might be breached.

UPDATE September 16th: Given another uptick and the current weather forecast, I'm ready to call the minimum for IJIS SIE V1 on September 12th at 5,000,313 km2. Apparently the high was too big and the pressure gradient too low to prolong things (see below). --- This blog post should perhaps ha...

Beaufort Sea continues to look interesting.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.11.html
Just from eyeballing the CT area chart it looks like this year wouldn't be out of place in the late-1980's and late-1990s. It looks like for each year since 2007 the Beaufort Sea has been in negative anomaly territory for more than half the year. This year it's looking like it's going to be negative for little more than 2 months. Given the endless observations of cracked and rotten ice in the region it seems rather remarkable.

UPDATE September 16th: Given another uptick and the current weather forecast, I'm ready to call the minimum for IJIS SIE V1 on September 12th at 5,000,313 km2. Apparently the high was too big and the pressure gradient too low to prolong things (see below). --- This blog post should perhaps ha...

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2012 period (NSIDC has ...

Neven, I think at some point you're going to have to stop being surprised at the lack of melt (or the persistence of extent) this year :P
It looks like this might be a 'new high' post the 2007 MYI clear out. It may be better understood as part of the natural variability and if we want to understand what's going on then we should be looking at the average extent since 2007 rather than expecting records to be broken. There is probably too much focus on record-breaking in the arctic. Given that ice can persist (or fail to persist) for 5 years or more suggests we should be trying to understand processes on that timescale as well.
Not only has a lot of FYI survived but so has much of the SYI (2nd) which is going to start showing up in the MYI category next year. It possible that at least a bit of a 'recovery' in the MYI is on the cards.

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2012 period (NSIDC has ...